docs: def get_dip(self):
          """
          Return the fault dip as the average dip over the mesh.
  
          The average dip is defined as the weighted mean inclination
          of all the mesh cells. See
          :meth:`openquake.hazardlib.geo.mesh.RectangularMesh.get_mean_inclination_and_azimuth`
  
          :returns:
              The average dip, in decimal degrees.
          """
          # uses the same approach as in simple fault surface
          if self.dip is None:
              mesh = self.mesh
              self.dip, self.strike = mesh.get_mean_inclination_and_azimuth()
          return self.dip